Mark Nicholas Gray MBE is a former colonel in the British Royal Marines, as of 2021[update] running a floating armoury company in the ocean area subject to piracy based in Somalia and nearby countries.

Gray, on his own initiative and exceeding his authority, opened the spillway gate and reduced the level of water in the lake by several metres; when the explosives were detonated the dam did not fail.

[4] In 1992 Gray, with the rank of major, opened a sluice gate on top of the Peruća dam in Croatia shortly before the occupying Serbs detonated explosives, protected by land mines and booby traps, deep inside it.

"This was an attempt to use the 540 million cubic metres of stored water as a weapon of mass destruction to the downstream land and population, " said Professor Back.

At each of these three points the top of the dam, made of rock fill with a clay core, sagged by two metres, said Professor Back, who was a member of a British team despatched by the Overseas Development Administration to inspect it and advise on repairs after the Croatians reoccupied it.

With fighting continuing in the surrounding hills, engineers had to race against time before the ongoing erosion of the dam's clay core caused a blow-through and total collapse.

[6] In 1998, while in command of Z Company, 45 Commando Royal Marines he took part in Operation Tellar, providing relief in Nicaragua in the wake of Hurricane Mitch[7] and in 1999 an exercise in the United States.

He has had staff appointments at the Permanent Joint Headquarters, Navy Resources and Plans in the Ministry of Defence, the Headquarters of the Multi-National Force – Iraq in Baghdad and the US Joint Chiefs of Staff in The Pentagon (as the deputy CDS liaison officer during the build up and conduct of the 2003 Iraq invasion), at the end of which he was accorded the privilege of addressing both US Houses of Congress, "one of the few Royal Marines to have entered the Capitol Building in uniform since his predecessors burned it down on 24 August 1814 ".